Surgical guides

ABSTRACT

A drill guide uses a hole in a layer to guide a drill along an axial trajectory while permitting off-axis excursions of the drill during use. A number of such drill guides at varying heights from a target surface may be used sequentially or concurrently to enforce the axial trajectory in three dimensions during a surgical operation. A drill guide may include a hole in a layer that establishes a single point along the axial trajectory, or the drill guide may include multiple layers in a single device to establish two or more points along the trajectory while allowing off-axis insertion of a drill into the guide. The drill guide may be cuttable to accommodate intraoperative changes to the axial trajectory. In embodiments, a window or the like may be provided to permit a surgeon to view drill depth, drill orientation, the surgical site and the like during a procedure.

RELATED APPLICATIONS

This application claims the benefit of U.S. Prov. App. No. 61/260,065filed on Nov. 11, 2009, the entire content of which is herebyincorporated by reference.

BACKGROUND

The invention relates to surgical drill guides for use in dental surgeryand similarly constrained surgical and/or drilling operations.

Drill guides are commonly used by dental surgeons to align a drill orother cutting tool with an intended hole for a dental implant; however,existing drill guides have significant disadvantages. For example, somedrill guides require insertion of a drill in alignment with a cuttingtrajectory, which can present difficulties in confined spaces that offerlittle clearance or overhead. As another disadvantage, some drill guidesblock a surgeon's view of the location where a drill meets bone or othertissue, thus impairing the surgeon's ability to obtain adequate visualverification of drill position and depth.

There remains a need for improved drill guide devices and methods foruse in dental surgery and similarly constrained surgical and/or drillingoperations.

SUMMARY

A drill guide uses a hole in a layer to guide a drill along an axialtrajectory while permitting off-axis excursions of the drill during use.A number of such drill guides at varying heights from a target surfacemay be used sequentially or concurrently to enforce the axial trajectoryin three dimensions during a surgical operation. A drill guide mayinclude a hole in a layer that establishes a single point along theaxial trajectory, or the drill guide may include multiple layers in asingle device to establish two or more points along the trajectory whileallowing off-axis insertion of a drill into the guide. The drill guidemay be cuttable to accommodate intraoperative changes to the axialtrajectory. In embodiments, a window or the like may be provided topermit a surgeon to view drill depth, drill orientation, the surgicalsite and the like during a procedure.

In one aspect, a device disclosed herein includes: a surgical guide fora dental procedure, the surgical guide including a first hole in a firstlayer, the first hole positioned to align a tool to an axial trajectoryat a first point along the axial trajectory and the surgical guideincluding a second hole in a second layer, the second layer verticallyspaced apart from the first layer along the axial trajectory and thesecond hole positioned to align the tool to the axial trajectory at asecond point along the axial trajectory; and a support to secure thesurgical guide in relation to a location where the axial trajectorymeets a target surface of a surgical site.

The target surface may include one or more of soft tissue and bone. Thetarget surface may include one or more of gingiva and a jawbone. Thesurgical site may include a dental implant site. The axial trajectorymay be a trajectory of a surgical drill into a surgical site. The axialtrajectory may be a trajectory of a surgical drill into a dental implantsite. The first hole and the second hole may be shaped and sized toalign an object to the axial trajectory including one or more of adrill, a surgical drill, a rotary tool, and a surgical hand tool. Thesupport may include a surface formed to dentition around the surgicalsite, thereby providing tooth support for the surgical guide. Thesurface may be formed to a full arch containing the surgical site. Thesupport may include a surface formed to bone around the surgical site,thereby providing bone support for the surgical guide. The support mayinclude one or more bone attachment points for securing the device to ajawbone. The support may include a surface formed to soft tissue aroundthe surgical site, thereby providing soft tissue support for thesurgical guide. The support may be shaped and sized to provide gingivalsupport for the surgical guide. The support may be shaped and sized toprovide skin support for the surgical guide. The first layer may contactthe target surface in an area surrounding the first hole when the deviceis placed for use at the surgical site. The second layer may be spacedapart from the target surface in an area surrounding the second holewhen the device is placed for use at the surgical site.

The second hole may have a diameter larger than the first hole. Thedevice may further include a space between the first layer and thesecond layer that permits an insertion of the tool off-axis from theaxial trajectory. The second layer may include one or more visiblealignment marks to assist a user in locating a center of the first hole.The first layer may include one or more additional visible alignmentmarks to assist the user in locating a center of the second hole. Thedevice may include an opening for physical access to a space between thefirst layer and the second layer. The device may include an opening forphysical access to the surgical site. The device may include a windowfor visual inspection of the target surface while the surgical guide maybe in use. The device may include a window for visual inspection of theaxial trajectory between the first layer and the second layer. Thedevice may be fabricated from a cuttable material. The axial trajectorymay be modified by enlarging one or more of the first hole and thesecond hole. The device may include a plurality of holes in each of thefirst layer and the second layer for a plurality of axial trajectories.

The device may include a plurality of devices each including a thirdhole positioned to align one of a number of progressively largerdiameter drills to the first point on the axial trajectory. Each of theplurality of devices further may include a fourth hole positioned toalign one of the number of progressively larger diameter drills to thesecond point on the axial trajectory. At least one of the first hole andthe second hole may have a sleeve that protects the surgical guideagainst a cutting edge of the tool. The sleeve may be formed of amaterial including one or more of a steel, a titanium, a glass, aplastic, and an aluminum. The surgical guide and the support may beformed of a clear material. The second hole may have a larger diameterthan the first hole, the second hole sized to accommodate a drill stopand the first hole sized to accommodate a drill without the drill stop.

In another aspect, a method disclosed herein include obtainingthree-dimensional data from beneath a surface of a surgical site;determining an axial trajectory for an implant to be placed in thesurgical site based upon the three-dimensional data; and fabricating adevice based upon the three-dimensional data, the device including asupport fitted to an area around the surgical site and a surgical guideincluding a hole that aligns a tool to the axial trajectory at a firstpoint along the axial trajectory while permitting off-axis excursions ofthe tool from the axial trajectory at a second point along the axialtrajectory away from the hole when the surgical guide may be placed foruse at the surgical site.

Fabricating the device may include manually fabricating the support andapplying the three-dimensional data to create the hole in the surgicalguide. Fabricating the device may include applying the three-dimensionaldata to generate a digital model of the surgical guide including thehole and fabricating the surgical guide from the digital model.Determining the axial trajectory for the implant may include positioningan implant with implant planning software. Fabricating the device mayinclude applying the three-dimensional data to create the hole in thedigital model of the device. Fabricating the device may include:capturing a physical impression of the surgical site; using the physicalimpression to fabricate a physical model; and using the physical modelto manually fabricate the device. Obtaining three-dimensional data mayinclude obtaining x-ray tomography data of the device and applying thethree-dimensional data to create a digital model of the device.Fabricating the device may include applying the three-dimensional modelto a computerized fabrication system to fabricate the surgical guide.The method may include creating the hole in the surgical guide with acomputer-controlled machine. The computer-controlled machine may includea computer-controlled milling machine. The computer-controlled machinemay include a computer-controlled drilling machine. Thecomputer-controlled machine may include one or more of a hole punch anda heated probe.

Obtaining three-dimensional data may include obtaining x-ray tomographydata from the surgical site. Obtaining three-dimensional data mayinclude creating a digital three-dimensional surface model of thesurgical site. Obtaining three-dimensional data may include creating adigital three-dimensional surface model of at least a portion of adental arch. Obtaining three-dimensional data may include creating adigital three-dimensional surface model of a full dental arch.Fabricating the device may include using the digital three-dimensionalsurface model to fabricate the device using a computerized fabricationsystem. The computerized fabrication system may include astereolithography system. The computerized fabrication system mayinclude a computerized milling machine. Fabricating the device mayinclude forming a material to a physical model of a dental archcontaining the surgical site. Forming the material to the physical modelmay include forming a sheet of material onto the physical model. Formingthe material to the physical model may include vacuum forming a plasticsheet onto the physical model. The surgical site may include one or moreof soft tissue and bone. The surgical site may include one or more ofgingiva and a jawbone. The axial trajectory may be a trajectory of asurgical drill into the surgical site. The axial trajectory may be atrajectory of a surgical drill into a dental implant site. The methodmay include adding one or more visible alignment marks to assist a userin locating a center of the hole. Fabricating the device may includefabricating the surgical guide from a clear material. Fabricating thedevice may include fabricating the support to secure the surgical guidein a desired location relative to the surgical site. The support mayinclude a surface formed to dentition around the surgical site, therebyproviding tooth support for the surgical guide. The surface may beformed to a full arch containing the surgical site. The support mayprovide bone support for the surgical guide.

The method may include adding one or more bone attachment points to thesupport for securing the support to a jawbone, thereby providing bonesupport for the surgical guide. The support may provide soft tissuesupport for the surgical guide. The support may provide gingival supportfor the surgical guide. The support may provide skin support for thesurgical guide.

Fabricating the device may include fabricating a two-layer surgicalguide having a first hole in a first layer centered around a first pointon the axial trajectory and a second hole in a second layer centeredabout a second point on the axial trajectory. Obtainingthree-dimensional data may include obtaining a digital three-dimensionalsurface model of the surgical site. Fabricating the device may includeusing the digital three-dimensional surface model to fabricate thesurgical guide using a computerized fabrication system. The computerizedfabrication system may include a stereolithography system. Thecomputerized fabrication system may include a computerized millingmachine. The axial trajectory may intersect a target surface of thesurgical site when the surgical guide may be placed for use at thesurgical site and the second layer may be vertically spaced apart fromthe target surface in a second area surrounding the second hole. Thefirst layer and the second layer may be vertically spaced apart toprovide a space that permits an insertion of the tool off-axis from theaxial trajectory. Fabricating the device may include fabricating awindow for physical access to a space between the first layer and thesecond layer. Fabricating the device may include fabricating a windowfor visual inspection of a target surface while the surgical guide maybe in use. Fabricating the device may include fabricating a window forvisual inspection of the axial trajectory between the first layer andthe second layer.

Fabricating the device may include fabricating the device from acuttable material wherein the axial trajectory can be modified byenlarging the hole. Fabricating the device may include fabricating thedevice with a plurality of holes for a plurality of axial trajectories.Fabricating a plurality of devices each including a progressively largerdiameter hole shaped and positioned to align one of a number ofprogressively larger diameter drills to the first point on the axialtrajectory. The method may include adding a sleeve to the hole thatprotects the surgical guide against a cutting edge of the tool. Thesleeve may be formed of a material including one or more of a steel, atitanium, a glass, a plastic, and an aluminum. Fabricating the devicemay include fabricating a window for visual inspection of the surgicalsite. Fabricating the surgical guide may include fabricating a windowfor physical access to the surgical site.

In another aspect, a method for realizing an axial trajectory of acutting process disclosed herein includes: guiding a first cutting toolwith a first guide at a first point along the axial trajectory when thefirst guide may be positioned for use at a surgical site whilepermitting movement of the first cutting tool away from the axialtrajectory at one or more other points along the axial trajectory; andguiding a second cutting tool with a second guide at a second pointalong the axial trajectory vertically spaced apart from a target surfacewhen the second guide may be positioned for use at the surgical sitewhile permitting movement of the second cutting tool away from the axialtrajectory at the one or more other points along the axial trajectory.

The first point may lie on the axial trajectory where the axialtrajectory intersects a target surface. The first cutting tool may bethe same as the second cutting tool. The second cutting tool may have alarger diameter than the first cutting tool. The method may includeguiding a plurality of progressively larger diameter drills with thesecond guide. The method may include providing a plurality of guideswith a respective plurality of larger holes for at least one of thefirst point and the second point along the axial trajectory. The targetsurface may be a dental implant site. The target surface may be asurgical site. At least one of the first cutting tool and the secondcutting tool may include one or more of a drill, a surgical drill, arotary tool, and a surgical hand tool. The first guide and the secondguide may be integrated into a single device for concurrent use. Themethod may include supporting the single device with a support includingone or more of a bone support, a tooth support, and a soft tissuesupport. The first guide and the second guide may be physically separatedevices. The first guide and the second guide may include progressivelylarger holes and the first guide and the second guide may beprogressively applied to enforce the axial trajectory for progressivelylarger tools. The method may include supporting one of the physicallyseparate devices with a support including one or more of a bone support,a tooth support, and a soft tissue support.

At least one of the first cutting tool and the second cutting tool mayinclude a drill with a drill stop. At least one of the first guide andthe second guide may include a window for visual access to the surgicalsite when placed for use at the surgical site. At least one of the firstguide and the second guide may include a window for physical access tothe surgical site when placed for use at the surgical site. The firstguide may include one or more visible alignment marks to assist a userin centering the first cutting tool on the axial trajectory. The secondguide may include one or more visible alignment marks to assist a userin centering the second cutting tool on the axial trajectory. At leastone of the first guide and the second guide may be formed of a cuttablematerial. The method may include cutting at least one of the first guideand the second guide to adjust the axial trajectory. The first guide mayinclude a hole for the first cutting tool, and the method may includeadding a sleeve to the hole to protect against a cutting edge of thefirst cutting tool. The second guide may include a hole for the secondcutting tool, and the method may include adding a sleeve to the hole toprotect against a cutting edge of the second cutting tool. At least oneof the first guide and the second guide may be formed of a clearmaterial.

In another aspect, a method disclosed herein includes obtainingthree-dimensional data from beneath a target surface of a surgical site;determining an axial trajectory for an implant to be placed in thesurgical site based upon the three-dimensional data; and fabricating adevice, the device including: a surgical guide formed of a hole in alayer that aligns a tool to the axial trajectory when the surgical guidemay be placed for use at the surgical site; an interior space along theaxial trajectory within the device; a window in a side of the device foraccess to the interior space; and a support to secure the surgical guidein relation to the surgical site.

The three-dimensional data from beneath the target surface may includenon-surface, interior data from within one or more dental structures.Access to the interior space may include physical access. Access to theinterior space may include visual access. The layer may be a thin layerthat permits movement of the tool away from the axial trajectory at oneor more points along the axial trajectory. The interior space may bebetween the layer and the target surface when the device may be placedfor use at the surgical site. The layer may be a thick layer thatconfines the tool to the axial trajectory. The window may provide a viewof the axial trajectory where the axial trajectory intersects the targetsurface when the device may be placed for use at the surgical site. Thewindow may provide a view of the axial trajectory where the axialtrajectory intersects the layer. The window may include a transparentsurface of the device. The axial trajectory may be a trajectory of asurgical drill into a dental implant site. The axial trajectory may be atrajectory of a surgical drill into the surgical site. The targetsurface may include one or more of soft tissue and bone. The targetsurface may include one or more of gingiva and a jawbone. The surgicalsite may include a dental implant site.

The hole may be shaped and sized to align an object including one ormore of a drill, a surgical drill, a rotary tool, and a surgical handtool to the axial trajectory. The support may include a surface formedto dentition around the surgical site, thereby providing tooth supportfor the surgical guide. The surface may be formed to a full archcontaining the surgical site. The support may be shaped and sized toprovide bone support for the surgical guide. The support may include oneor more bone attachment points for securing the surgical guide to ajawbone, thereby providing bone support for the surgical guide. Thesupport may be shaped and sized to provide soft tissue support for thesurgical guide. The support may be shaped and sized to provide gingivalsupport for the surgical guide. The support may be shaped and sized toprovide skin support for the surgical guide.

The layer may contact the target surface in an area surrounding the holewhen the surgical guide is placed for use at the surgical site. Thelayer may be spaced apart from the target surface in an area surroundingthe hole when the surgical guide is placed for use at the surgical site.The window may be positioned between the layer and the target surface.The window may be positioned between the layer and a second layer thatabuts the target surface. The interior space may be coextensive with thehole. The interior space may include a volume between the layer and thetarget surface that permits an insertion of the tool off-axis from theaxial trajectory. The surgical guide may include a second hole in asecond layer that aligns the tool to the axial trajectory when thesurgical guide may be placed for use at the surgical site. Fabricatingthe surgical guide may include fabricating the surgical guide from acuttable material. The method may include modifying the axial trajectoryby enlarging the hole.

The surgical guide may include a plurality of holes in the layer for aplurality of axial trajectories at different locations in a dental arch.The method may include fabricating a plurality of surgical guides, eachincluding a progressively larger hole to align one of a number ofprogressively larger diameter drills to the axial trajectory. The methodmay include adding a sleeve to the hole that protects the surgical guideagainst a cutting edge of the tool. The sleeve may be formed of amaterial including one or more of a steel, a titanium, a glass, aplastic, and an aluminum.

In another aspect, a device disclosed herein includes a surgical guide,the surgical guide including a hole in a layer, the hole positioned toalign a tool to an axial trajectory at a first point along the axialtrajectory, and the hole including a tapered wall that provides adiameter that varies along an axis of the hole, wherein the diameterranges between a narrowest section and a widest section; and a supportto secure the surgical guide in relation to a location where the axialtrajectory meets a target surface of a surgical site.

The device may include a second hole in a second layer vertically spacedapart from the first layer, the second hole positioned to align the toolto the axial trajectory at a second point along the axial trajectory.The target surface may include one or more of soft tissue and bone. Thetarget surface may include one or more of gingiva and a jawbone. Thesurgical site may include a dental implant site. The axial trajectorymay be a trajectory of a surgical drill into a surgical site. The axialtrajectory may be a trajectory of a surgical drill into a dental implantsite. The hole may be shaped and sized to align an object to the axialtrajectory including one or more of a drill, a surgical drill, a rotarytool, and a surgical hand tool. The support may include a surface formedto dentition around the surgical site, thereby providing tooth supportfor the surgical guide. The support may include a surface formed to bonearound the surgical site, thereby providing bone support for thesurgical guide. The support may include one or more bone attachmentpoints for securing the device to a jawbone. The support may include asurface formed to soft tissue around the surgical site, therebyproviding soft tissue support for the surgical guide. The layer may bevertically spaced apart from the target surface in an area surroundingthe hole when the device may be placed for use at the surgical site. Thelayer may include one or more visible alignment marks to assist a userin locating a center of the hole.

The device may include a window for visual inspection of the targetsurface while the surgical guide may be in use. The device may include awindow for physical access to the surgical site when the device may beplaced for use. The device may be fabricated from a cuttable material.The device may include a plurality of holes in the layer for a pluralityof axial trajectories. The hole may include a sleeve that protects thesurgical guide against a cutting edge of the tool. The sleeve may beformed of a material including one or more of a steel, a titanium, aglass, a plastic, and an aluminum. The surgical guide and the supportmay be formed of a clear material. The layer may have a thickness lessthan the diameter of the hole at the widest section. The layer may havea thickness less than the diameter of the hole at the narrowest section.The layer may have a thickness greater than the diameter of the hole atthe narrowest section. The layer may have a thickness greater than thediameter of the hole at the widest section. The diameter of the hole atthe widest section may be at least ten percent greater than the diameterof the hole at the narrowest section. The diameter of the hole at thewidest section may be at least twenty-five percent greater than thediameter of the hole at the narrowest section. The widest section may beon a top of the layer and the narrowest section may be on a bottom ofthe layer. The narrowest section may be at a surface of the layerproximal to the location where the axial trajectory meets the targetsurface of the surgical site. The narrowest section may be at a surfaceof the layer distal to the location where the axial trajectory meets thetarget surface of the surgical site. The narrowest section may bebetween a top surface and a bottom surface of the layer.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of theinvention will be apparent from the following description of particularembodiments thereof, as illustrated in the accompanying drawings inwhich like reference characters refer to the same parts throughout thedifferent views. The drawings are not necessarily to scale, emphasisinstead being placed upon illustrating the principles of the invention.

FIG. 1 shows a surgical drill guide for dental applications.

FIG. 2 illustrates bone support for a surgical guide.

FIG. 3 illustrates soft tissue and bone support for a surgical guide.

FIG. 4 shows a surgical guide.

FIG. 5 shows a surgical guide.

FIG. 6 shows a method for performing a dental implant procedure.

FIG. 7 shows a two-layer surgical guide.

FIG. 8 is a cross-sectional view of a two-layer surgical guide.

FIG. 9 is a cross-sectional view of a two-layer surgical guide.

FIG. 10 shows a surgical guide with a window.

FIG. 11 shows a surgical guide with a window.

FIG. 12 is a cross-sectional view of a surgical guide.

FIG. 13 is a cross-sectional view of a surgical guide.

FIG. 14 shows alignment marks for a hole in a surgical guide.

FIG. 15 shows a system for creating a surgical guide.

DETAILED DESCRIPTION

Described herein are devices and methods for enforcing an axialtrajectory during a drilling operation. In particular, exemplaryembodiments of the invention include devices and methods for guiding asurgical drill along a predetermined axial trajectory during a dentalimplant procedure. As used herein, the term “axial trajectory” refers toa straight line defined by at least two separate points thatcharacterize an intended path (typically the center of the path) for adrill into a site such as a surgical site. The axial trajectory for aparticular surgical operation may be determined, for example, usingplanning software or the like prior to the surgical operation based uponthree-dimensional data acquired from the surgical site. It will beunderstood that while the following description depicts lower-jaw drillguides, one of ordinary skill in the relevant art may readily adapt thesurgical guides and related procedures to an upper jaw, and all suchvariations are intended to fall within the scope of this disclosure.

FIG. 1 shows a device 100 including a surgical guide 101 and a support102. In general, the surgical guide 101, which may be a surgical drillguide for use in dental procedures or the like, may include one or moreholes 110 to align a drill with an axial trajectory 112. The support 102may be fitted to the teeth 104, soft tissue 106, and/or bone 108 inorder to retain the surgical guide 101 relatively immobile with respectto the bone 108 during a drilling operation. It will be understood thatwhile terms such as “surgical guide” or “drill guide” are typically usedin the art to describe the entire device 100 depicted in FIG. 1, thefollowing description refers periodically to a “surgical guide” insteadas that portion of such a device 100 that physically retains a drill orother tool or object along the axial trajectory 112 in order todistinguish this functional portion from the support 102, which operatesto secure the surgical guide 101 (and the axial trajectory 112 definedby same) relative to a target location. Thus depending on the context a“surgical guide” as used herein may refer specifically to a portion of adevice that has one or more holes (or other guiding elements), or mayrefer generally to an entire device that is used as a drill guide or thelike.

The support 102 may be fabricated to conform to any features within apatient's mouth including the teeth 104, soft tissue 106, and bone 108.This design may be derived for example from a model of a patient'sdental arch or from three-dimensional digital scans or otherthree-dimensional data from a surgical site. In general, the support 102secures the surgical guide 101 in relation to a location where the axialtrajectory 112 meets a target surface 113.

The support 102 may provide tooth support, soft tissue support, and/orbone support. As depicted, the support 102 may include a surface 116(the interior surface of the device 100) formed to dentition around adental implant site, thus providing tooth support. The surface 116 maybe formed to a full arch containing the dental implant site, or someportion thereof. The support 102 may also or instead provide soft tissuesupport with the surface 116. This may include skin support, gingivalsupport, or more generally any soft tissue support by which the surface116 is formed to the skin, gingiva, gum, mucosa, and the like. Thesupport 102 may also, or instead, provide bone support, which may in useinvolve supplemental surgical procedures such as cutting and lifting aflap of the soft tissue 106 to expose the bone 108 so that the surface116 can be placed in direct contact with the bone 108, or using one ormore screws or other attachments to secure the support 102 directly tothe bone 108. More generally, the support 102 may provide support to fixthe surgical guide 101 relative to the bone 108 using any or all of theabove techniques, and the support 102 may usefully cover more or less ofthe dentition and surrounding tissue than depicted, all withoutdeparting from the scope of this disclosure.

While not visible in FIG. 1, it will be appreciated that the targetsurface 113 extends to a location beneath the surgical guide 101 wherethe axial trajectory 112 intersects the soft tissue 106 or bone 108 sothat a drill or other tool may be directed into the jaw at anappropriate location and orientation. As used herein, the term “targetsurface” is generally intended to refer to an exterior, two-dimensionalsurface of a surgical site that includes a location where a drill, tool,or implant is intended to enter the surgical site, unless a differentmeaning is specifically provided or otherwise clear from the context. Ingeneral, the target surface follows surface contours of a dental archthat is prepared for surgery and includes a single point of intersectionwith the axial trajectory 112. The target surface 113 may include anysoft tissue 106 or bone 108 as described herein.

While the systems and methods described below are useful in dentalsurgery, it will be appreciated that these systems and methods may moregenerally be used at a surgical site, which as used herein is intendedto refer to a volume surrounding and including a location where surgerywill be performed. This may include a dental implant site where a dentalimplant is to be placed in a jawbone or more generally any site alongthe dental arch or elsewhere that a drill or other cutting tool mightusefully be guided in a surgical procedure.

FIG. 2 illustrates bone support for a surgical guide. In a bonesupported guide 200, a flap of the soft tissue 202 may be cut and liftedas illustrated in order to expose the bone 204 underlying the softtissue 202. In other embodiments, a portion of the gum may be cut awayusing a punch or similar device to expose the underlying bone around thedrill site. One or more screws 206 may also be used to secure the bonesupported guide 200 to the bone 204. It will be appreciated that, whileintroduced in the context of a prior art drill guide, bone support mayalso be used with the drill guides described below.

FIG. 3 illustrates soft tissue and bone support for a surgical guide.The guide 300 may be placed directly in contact with soft tissue 302such as skin or gums, and one or more screws 306 may be used to furthersecure the guide 300 to the underlying bone 304. It will be appreciatedthat, while introduced in the context of a prior art drill guide, boneand soft tissue support may also be used with the drill guides describedbelow.

Returning to FIG. 1, the teeth 104 (directly beneath the surgical guide101 and/or support structure 102 in FIG. 1) may be any human or animaldentition. In a dental application, the soft tissue 106 may, for exampleinclude gums, gingiva, mucosa, and/or skin, as well as combinations ofthese. The bone 108 may include a jawbone. It will be understood thatthe teeth 104, bone 108 and soft tissue 106 are depicted in thegeneralized form of a dental model, and that the shape of these featuresin vivo may vary significantly from this abstract representation. Inpractice, while the device 100 might be test-fitted to such a dentalmodel, the device 100 is intended for use in vivo where an opposingarch, tongue, lips, and other anatomical features and the like are alsopresent.

One or more holes 110 may be provided within the surgical guide 101 thatare shaped, sized, and oriented to align a drill, hand cutting tool, orother tool or item with the axial trajectory 112. Further, while thedevice 100 may be specifically designed and used to guide a drill, itwill be understood that any object may be usefully aligned with thedevice 100 such as a grinding bit, a drill, a surgical drill, a surgicalhand tool (or any other surgical tool), a dental implant screw, ahealing abutment, an implant, and so forth. It will be noted that in theprior art device 100 of FIG. 1, the hole(s) 110 are relatively deep, andas a result the elongated cylindrical interior shape of the hole(s) 110fully constrains a drill of matched diameter (usually very slightlysmaller than the hole(s) 110) to the axial trajectory 112, and does notpermit excursions of such a drill positioned in the device 100 away fromthe axial trajectory 112 along the length of the drill. Even withsmaller drills, the hole(s) 110 may tend to bind a drill that ismisaligned to the axial trajectory 112 during use.

While three holes 110 are depicted, it will be understood that thesurgical guide 101 may include fewer or more holes. Thus for example,the surgical guide 101 may include one hole, two holes, three holes,four holes, or any other suitable number of holes, such as for multipleimplants that are planned for a patient using the device 100. It willalso be appreciated that each hole 110 may include a sleeve 114 thereinthat protects the surgical guide 101 against a cutting edge of a drillor other tool. The sleeve 114 may be formed of a steel, a titanium, aglass, a plastic, an aluminum, or any other material or combination ofmaterials suitably hardened to resist cutting or abrasion from a cuttingtool such as a drill.

The axial trajectory 112 may be determined using any suitablecomputerized or manual case planning tools. For example a dental surgeonmay use implant planning software or the like based uponthree-dimensional tomographic data or other topology information todetermine an appropriate axial trajectory to drill a hole into which adental implant is to be placed. This surgical plan may be transferred toa patient by fabricating a device, such as any of the devices describedherein, that is fitted to a patient's mouth and that includes one ormore holes that enforce the axial trajectory.

When placed for use at a surgical site in the patient's mouth (e.g.,aligned and fitted to gums, teeth, and so forth), the device may be usedto assist a surgeon in creating a properly positioned and oriented holefor placement of the implant. It will be understood that the devicesherein are sometimes described in terms of the context in which they aredeployed, e.g., placed for use at a surgical site. This may includereferences to the bone, teeth, and/or soft tissue and so forth thatposition and support a guide, as well as the target surface where a holeis to be made. While this associated physical context may affect theshape or configuration of a guide, these items are not to be construedas features of the disclosed invention unless otherwise clearly statedto the contrary.

As a significant disadvantage, a surgical drill must be inserted intothe device 100 of FIG. 1 on-axis, that is, pre-aligned with the axialtrajectory 112, which may prove difficult in confined spaces such as inpatients with limited mouth opening and/or in the posterior portions ofan arch where the teeth or other anatomy of an opposing arch affordlittle maneuvering room. In addition, a drill may bind if misaligned ina long tube, even where the drill has a substantially smaller diameterthan the guide. As another disadvantage, the device 100 may obstruct asurgeon's view of the location where a drill intersects the targetsurface, which may prevent the surgeon from viewing drill depth or otheraspects of a procedure. Improved drill guides, and methods of usingsame, are now discussed in greater detail.

FIG. 4 shows a surgical guide. In general, the device 400 includes asupport 402 and a surgical guide 404, which may include any of thesupports and surgical guides described above, with differences as notedin the following description.

The device 400 may be fabricated using any of a variety of techniques,including casting or molding the device 400 from a model of thepatient's mouth. The device 400 may also or instead be fabricated basedupon three-dimensional data, along with any suitable rapid prototypingsystem(s) including without limitation three-dimensional printing,stereolithography, computerized milling and so forth. More generally anycomputer-driven fabrication technique may be employed includingcomputerized milling, machining, drilling, and so forth. A digital modelof the device 400 may be manipulated in a computer environment beforefabrication in order to add holes, alignment marks, or other markingssuch as patient identification data and so forth.

Three-dimensional data may take a variety of forms (e.g., surface,volumetric, etc.) and may be obtained from a variety of imagingtechniques. Thus for example, in various uses described herein,three-dimensional data may be 602 obtained, e.g., using any of a varietyof three-dimensional surface scanning technologies such as image-based,video-based, structured-light, time-of-flight, or other techniques.Non-surface data may also be obtained, such as interior datacharacterizing structures below the surface, such as data obtained fromCT scans, x-ray tomography, and so forth. In general, as used herein,data beneath a surface will be understood to refer to such interior,volumetric, or non-surface data (which may of course extend up to andinclude a surface), without regard to the relative orientation of thesurface and the interior in general three-dimensional space. It willfurther be appreciated that surface data and interior data may beregistered to provide a digital model with both surface data andinterior data. More generally, any form of three-dimensional data thatcharacterizes the relevant surfaces and structures for the design andfabrication of drill guides may be suitably adapted to use with thesystems and methods described herein. In addition, dental structurescharacterized by such three-dimensional models may include any anatomicstructure associated with a drilling procedure including withoutlimitation teeth, jawbones, maxillary sinus, nerve canals, and so forth.

In general, the support 402 secures the surgical guide 404 in relationto a location where an axial trajectory 406 meets a target surface 408.The support 402 may include any of the supports described aboveincluding a tooth support, a bone support, a soft tissue support, or anycombination of the foregoing. While the axial trajectory 406 is depictedas substantially normal to the target surface 408, it will be understoodthat the axial trajectory 406 may have any suitable orientation andposition for forming a desired hole in the bone 410 for a dentalimplant.

The surgical guide 404 may include one or more holes 412 in a layer 420to align a tool to the axial trajectory 406 at a first point 416 alongthe axial trajectory 406 while permitting movement of the tool away fromthe axial trajectory 406 at a second point 418 along the axialtrajectory 406, as indicated generally by an arrow that depicts apossible excursion from the axial trajectory 406 at the second point418. In general, the surgical guide 404 is formed of a layer 420 of anysuitable material or combination of materials. It will be noted in acomparison to the prior art surgical guide 101 of FIG. 1 that thesurgical guide 404 disclosed herein uses a thin layer. The hole 412 inthe thin-layer guide serves to retain a drill or other device ofcorresponding diameter (usually slightly smaller in diameter than thehole) in a position centered on the axial trajectory 406 at the firstpoint 416 without constraining axial rotation of the drill at positionsaway from the first point 416, such as the second point 418. As will bediscussed in greater detail below, a second guide may serve to defineanother point along the axial trajectory 406, such as the second point418 or any other point spaced away from the target surface 408, and maybe used in conjunction with the surgical guide 404 to impose a fixedposition and orientation on a drill corresponding to an axial trajectoryfrom a surgical plan. Thus the layer 420 should be sufficiently thin topermit axial movement of a matched drill at points away from the firstpoint 416, while being sufficiently thick to provide strength andrigidity that helps to retain a drill bit centered on the first point416 during a drilling operation.

It should be clear from the foregoing that a specific thickness of thelayer 420 is not required to permit substantial off-axis movement of atool that is substantially matched (e.g., having a slightly smallerdiameter) in size to the hole 412. For example the layer 420 may have athickness in an area about the hole 412 that is less than a diameter ofthe hole 412, or less than a radius of the hole 412 (e.g., a onemillimeter diameter hole in a 0.5 millimeter layer), or significantlyless than a radius of the hole 412 (e.g., a two millimeter hole in a 0.5millimeter layer). This property of off-axis movement may also becharacterized in terms of the degree of off-axis maneuverabilityafforded to a tool that is substantially matched to the hole 412 (thatis, having the same nominal diameter, although the tool necessarily hasa slightly smaller diameter if it is not intended to cut the surgicalguide 404 during use). For example, the surgical guide 404 may permit afive degree off-axis excursion of a one millimeter diameter drill placedin a one millimeter diameter hole, a ten degree excursion of a onemillimeter diameter drill placed in a one millimeter diameter hole, andso forth (generally without damaging or otherwise compromising theguide). It will further be understood that a thickness of the surgicalguide 404 may be varied according to other factors such as the type ofmaterial used to form the layer 420, the degree of flexibility desiredfor orientation of a drill about the axial trajectory 406, whether thelayer 420 is intended to be cuttable for intra-operative modificationsto the axial trajectory 406, the type of drill or tool used, and soforth. All such variations are intended to fall within this disclosure,and may be readily distinguished from the surgical guides of the priorart which purposefully and strictly constrain the position andorientation of a matched drill bit along its entire length to the axialtrajectory 406.

As depicted in FIG. 4, the layer 420 may contact the target surface 408in an area such as the surface area, volume or other space surroundingthe hole(s) 412. This configuration may, for example, be useful forpositioning an initial pilot hole or the like according to the axialtrajectory 406. In other embodiments described below, the layer 420 maybe spaced apart from the target surface in an area surrounding the hole,such as to impose the second point 418 of the axial trajectory 406 ontoa drill bit or other tool with which the surgical guide 404 is used.

While a single axial trajectory 406 is depicted, it will be understoodthat the surgical guide 404 may include a plurality of holes 412 for aplurality of axial trajectories 406. The hole(s) 412 may be sized for adrill of a particular diameter, or the hole(s) 412 may be sized for athin, sharp instrument that can be used to create a bleeding point orother mark at the first point 416 to assist a surgeon in creating aninitial pilot hole or the like. The surgical guide 404 may also orinstead include a visible marking such as an ‘x’ or any other suitablemarking(s) and/or surface features to mechanically and/or visually guidea surgeon to a correct starting location for a drill. It will beappreciated that the bleeding point may also be established using aprior art tube-type guide or any other technique, without departing fromthe scope of this disclosure.

The first point 416 may be at a location where the axial trajectory 406intersects the target surface 408. This location may, for example,include a dental implant site as generally depicted in FIG. 4, and theaxial trajectory 406 may be a trajectory of a surgical drill into thedental implant site. More generally, the location may be any surgicalsite, and the axial trajectory 406 may be a trajectory of a surgicaldrill into the surgical site. Still more generally, the principlesdisclosed herein may be applied in any context, surgical or otherwise,where constraints such as maneuvering room, visibility, and flexibilitycan be usefully addressed with the methods and systems disclosed herein.

In one aspect, the support 402 and/or the surgical guide 404 may befabricated from a clear plastic or other transparent or translucentmaterial that permits a surgeon to view the target surface 408 and/orsurrounding areas during a procedure. The support 402 and/or thesurgical guide 404 may be formed of a cuttable material to permitcustomization of the device 400, such as according to a surgical planthat has been revised after fabrication of the device 400. Where thedevice 400 is fabricated from a cuttable material, the axial trajectorycan be modified, for example, by enlarging the hole with a drill or anyother hand cutting tool or powered cutting tool. In other embodiments,each hole 412 may include a hardened ring of stainless steel or anyother cut-resistant, biocompatible material such as the materialsidentified above to provide an abrasion-resistant sleeve. A variety ofcuttable, cut-resistant, biocompatible, and/or clear materials are knownin the art and may be suitably adapted to use with the systems andmethods disclosed herein.

FIG. 5 shows a device 500 including a support 502 and a surgical guide504. The support 502 and the surgical guide 504 may, for example, be asshown and described with reference to FIG. 4, with differences notedbelow.

A layer 506 of material that forms the surgical guide 504 may be spacedapart from a target surface 508 in an area 510 where an axial trajectory512 intersects the target surface 508, which area 510 may include anysurrounding surfaces and/or volume. The layer 506 may be of any shape orsize consistent with adequate support of the surgical guide 504 in amanner to retain a drill or other tool as described herein. In oneaspect, the separation of the layer 506 from the target surface 508provides an interior space 513 around the axial trajectory 512 includinga working volume that permits an insertion of a tool off-axis from theaxial trajectory 512. In addition, the layer 506 may be shaped toinclude a window 514 with an opening for physical access to the spacebetween the layer 506 and the target surface 508. This window 514 may beused for access by a surgeon to the target surface 508 for cleaning,inspection, irrigation, suction, material or tool removal, or any otherpurpose. The window 514 may also or instead provide an opening forvisual inspection of the target surface 508 while the surgical guide 504is in use (e.g., with a drill inserted into one of the holes in thesurgical guide 504). The window 514 may include an opening for visualinspection along some or all of the axial trajectory 512 in the spacebetween the target surface 508 and the layer 506 of material. It will beunderstood that the window 514 or portions thereof may be formed of aclear material that provides visual access into areas enclosed by thesurgical guide 504 and/or the support 502 without affording physicalaccess.

A hole 516 in the surgical guide 504 can serve to guide or otherwiseretain a tool (not shown) at a point above or otherwise separated fromthe target surface 508. By using the device of FIG. 5 in combinationwith (e.g., sequentially with) the device of FIG. 4, the entire axialtrajectory 512 of a surgical plan can be enforced by using a first guide(such as the guide of FIG. 4) to establish a point where the axialtrajectory 512 intersects the target surface 508 and using a secondguide (such as the guide of FIG. 5) to establish a second point alongthe axial trajectory 512. By guiding a drill through the second guideinto the drill hole formed using the first guide, two points sufficientto establish the axial trajectory 512 are imposed on a drill. Where asurgeon wishes to make intra-operative modifications to the axialtrajectory 512, the first guide or the second guide may be modified bycutting or otherwise enlarging or re-shaping the hole to shift orre-orient the axial trajectory 512 at the first point, the second point,or both. Similarly, a bleeding point may be used to visually establishone point along the axial trajectory 512 on the target surface 508, andthe guide of FIG. 5 may be used to establish another point along theaxial trajectory 512. Either the bleeding point or the hole may bemodified intra-operatively as desired by the surgeon.

While each hole 516 is depicted as round, any regular or irregular,polygonal or curvilinear, or other shape, or any combination of theforegoing, may also or instead be employed. Thus for example, one ormore of the holes 516 may be a square, a hexagon, or other shape capableof retaining a substantially cylindrical drilling tool such as a drillor the like along a path defined by the axial trajectory 512. In anotheraspect, the holes 516 may be rectangular (or any other shape with a pairof long, parallel sides), thus permitting movement of the axis of a toolin a single plane, e.g., for off-axis insertion of a drill or formanual, intraoperative adjustments to the axial trajectory 512. In suchembodiments, alignment marks may be provided to indicate a desiredorientation within the plane for the axial trajectory 512.

Numerous variations to the device 500 are possible. For example, thedevice 500 may include any number of holes 516 for any number of axialtrajectories 512. In one aspect, each hole 516 may have a funnel-shapedinterior wall as described in greater detail below. It will also beunderstood that the guide 504 and support 502 may have a variety ofphysical shapes and configurations without departing from the scope ofthis disclosure. For example, while the device 500 is depicted asresting on a distal or posterior region of the target surface 508, thissupporting structure may be removed, such as to provide a greaterworking volume for off-axis insertion of a drill into one of the holes516 in the posterior region.

It will be further understood that a number of devices may be providedhaving progressively larger hole sizes for progressively larger drills,such as a narrow guide for a pilot hole and a larger guide for a finalhole, as well as any number of intervening sizes consistent with aparticular cutting operation. In another aspect, a first guide with asmall diameter (e.g., 0.7 millimeters for creation of a bleeding pointor two millimeters for creation of a pilot hole) may be provided thatrests on the target surface 508 where the axial trajectory 512intersects the target surface 508, and a second guide with a larger hole(e.g., 5.5 millimeters for a final, largest drill size) may be providedthat is spaced away from the target surface 508. A narrow diameter pilotdrill may be placed into the hole 516 in the second guide and maneuveredinto the pilot hole or bleeding point previously created. This secondguide may include visual markers to assist a user in centering the pilotdrill and a series of progressively larger drills until a final holediameter is achieved. In another aspect, this may include two or more ofthe device 400 depicted in FIG. 4 and two or more of the device 500depicted in FIG. 5. Thus in one aspect there is disclosed herein aplurality of devices each including a hole positioned to align one of anumber of progressively larger diameter drills to a first point (whichmay be a point on the target surface 508 or a point away from the targetsurface 508) on the axial trajectory 512. In another aspect, theplurality of devices may include holes to align drills to a number ofdifferent points on the axial trajectory 512, and/or holes to aligndrills to a number of different axial trajectories.

FIG. 6 shows a method for performing a dental implant procedure usingthe surgical guides described herein. More generally, the followingmethod 600 realizes an axial trajectory of a cutting process, which maybe usefully employed in a dental implant procedure, or any othersurgical procedure that includes translating an axial trajectory from asurgical plan to a patient. Still more generally, the method 600 may beusefully employed in any context where an axial trajectory is transposedfrom a model to a physical object.

As shown in step 602, the method 600 may begin with data acquisition.This may include acquisition of three-dimensional data from beneath asurface of a surgical site, such as interior data obtained from withinone or more dental structures (e.g., teeth, bone, soft tissue, etc.)through x-ray tomography or any other suitable subsurface imagingtechnology. This may also or instead include an acquisition ofthree-dimensional surface data obtained using any suitable surfacescanning technology. This may also or instead include an acquisition oftwo-dimensional radiographs such as orthopantomographs or periapicals.This may also include an acquisition of three-dimensional information inthe form of physical models such as casts, molds, or impressionsrepresentative of a dental implant site and surrounding dentition,tissue, and the like.

Thus it will be understood that data acquisition may take a variety offorms. Data acquisition may include acquisition of a physical or analogmodel of a surgical site and/or teeth using, e.g., conventional dentalimpressioning to create a physical model and/or a cast for same. Dataacquisition may also or instead include a three-dimensional surface scan(using, e.g., video-based techniques, structured light techniques, orany other suitable three-dimensional surface scanning techniques) of asurgical site, or of a physical model produced from a dental impression,or of interior surfaces of a cast for a physical model. Data acquisitionmay also or instead include an x-ray tomographic scan or surface scan ofan acrylic shell or other vacuum-formed or similar thin layer cast of aphysical model or surgical site. Data acquisition may also include acapture of supplemental data such as prescription information derivedfrom a patient interview, questionnaire, or the like, or informationreceived from another treating physician.

As shown in step 604, the method 600 may include case planning todetermine a course of action for a dental procedure. In the case of adental implant, this may include selecting a suitable implant anddetermining an axial trajectory for a hole to receive an implant, or thelike. In general, positioning of the axial trajectory is influenced by avariety of factors such as the position, shape, and size of teeth, theavoidance of vital structures, and the existence of adequate bone volumearound the hole. Depending on the procedure, the axial trajectory may berealized using any number of drills (e.g., one to seven) of increasingsize from a smallest size for a pilot hole to a largest size for thefinal hole that will receive the implant. Case planning may also includean identification of other pre-surgical treatment(s) in preparation foran implant. Case planning may include the use of case planning software,including any of a variety of commercially available software tools, toassist in assessment of a surgical site and three-dimensionalpositioning and orientation of an axial trajectory.

As shown in step 606, the method 600 may include fabricating a number ofsurgical guides such as any of the guides described herein. This may forexample include interim steps such as a creation of stereolithographyfabrication files, milling machine instructions, or the like to controla computerized fabrication system including without limitation astereolithography system, a digital light processing system, acomputer-controlled milling machine, a three-dimensional printingsystem, or any other computer-driven process such as acomputer-controlled drill, lathe, and so forth, as well as anycombination of the foregoing. This may also include manual fabricationbased upon a physical model of a surgical site. For example a materialsuch as any pliable, curable material may be placed on the physicalmodel to capture a complementary shape, and then cured to a sufficienthardness for use as a support structure. Similarly, a sheet of materialsuch as plastic, which may be clear plastic, may be formed to thephysical model using vacuum forming or the like to produce the supportstructure. In one aspect, fabrication may include a combination ofmanual and automated steps. It will also be appreciated that fabricationas contemplated herein may include any number of interim fabrication anddata acquisition steps, such as fabricating an arch model usingstereolithography (or any other suitable technique for converting adigital model into a physical model), and using the physical arch modelfor subsequent scanning or fabrication steps such as preparing a shellthat will be further processed to fabricate a drill guide.

For example, a thin-layer guide such as various guides described abovemay be fabricated from a plaster model or the like to provide a form fora tooth support. The resulting cast may form a shell that maps thecontours of a surgical site in a physical form. The shell may then besubjected to further computerized processing to provide a surgicalguide. For example, an axial trajectory determined usingthree-dimensional data and case planning software may be mapped to themanually fabricated support structure or shell and used with acomputer-controlled milling machine or the like to accurately positionand create a hole for a surgical guide in the support. In anotheraspect, fabricating the surgical guide(s) may include fabricating theshell or support with an automated fabrication process and subsequentlymilling the hole(s) with a manual or automated milling process or thelike. In general, creating a hole with a computer-controlled machine asdescribed herein may include any suitable computer-controlled apparatus,such as a computer-controlled milling machine, a computer-controlleddrilling machine, a hole punch, a heated probe (where the support isformed of a meltable plastic or similar material), or any other machinethat can be programmed or operated with a computer to place a hole witha desired size in a desired location.

As shown in step 608, the method 600 may include guiding a first cuttingtool with a first guide, such as any of the surgical guides describedherein. This may include guiding the first cutting tool at a first pointalong the axial trajectory where the axial trajectory intersects atarget surface while permitting movement of the first cutting tool awayfrom the axial trajectory at one or more other points along the axialtrajectory. The first cutting tool may, for example, be a surgicaldrill. In another aspect, the first cutting tool may be a hand dentaltool such as an osteotome or other tool used to manually bore a hole fora dental implant. As another example, the first cutting tool may be asharp, pointed hand tool used to create a bleeding point at a desiredlocation. More generally, the first cutting tool may include a drill, asurgical drill, a rotary tool, a surgical hand tool, or any other toolthat might be guided along an axial trajectory. The target surface maybe a dental implant site, or more generally any surgical site.

As shown in step 610, the method 600 may include guiding a secondcutting tool with a second guide such as any of the surgical guidesdescribed herein. This may include guiding the second cutting tool at asecond point along the axial trajectory spaced apart from the targetsurface while permitting movement of the second cutting tool away fromthe axial trajectory at the one or more other points along the axialtrajectory, such as using one of the thin-layer guides described above.The first cutting tool may be the same as the second cutting tool, suchas where guides are sequentially applied to establish a point on thetarget surface and then a point away from the target surface for aparticular drill. Or the first cutting tool and the second cutting toolmay be different cutting tools. For example, the second cutting tool mayhave a larger diameter than the first cutting tool, such as with aseries of progressively larger cutting tools that result in a final holesize suitable for a dental implant (or other implant anchor or thelike). In another aspect, the second guide may be used to guide aplurality of progressively larger diameter drills. This may be suitablewhere, for example, the first guide centers a pilot hole or a bleedingpoint, and the hole in the second guide is over-sized relative to thepilot hole or bleeding point, but may nonetheless enforce the desiredaxial trajectory on a final drill matched to the size of the hole in thesecond guide. In this example, a dentist or surgeon may insert thesmaller drill into the hole in the second guide and maneuver the tip ofthe drill into the pilot hole or bleeding point and center the smallerdrill in the second guide by eyesight, or with the aid of visualalignment marks or the like on the second guide, aligning the drill withthe axial trajectory. In general, the second cutting tool may include adrill, a surgical drill, a rotary tool, a surgical hand tool, or anyother tool that might be guided along an axial trajectory.

In one aspect, the first guide and the second guide may be separateguides as generally discussed above. In another aspect, the first guideand the second guide may be integrated into a single physical devicesuch as the two-layer device described below.

As shown in step 612, the method 600 may optionally include providingand using a plurality of guides with a respective plurality ofprogressively larger holes for at least one of the first point and thesecond point along the axial trajectory. Thus any number ofprogressively larger drills may be guided with suitably matched surgicalguides.

As shown in step 614, after a hole of suitable diameter centered on theaxial trajectory has been prepared, a dental implant may be insertedinto the resulting hole. This may include, for example, a self-tappingimplant screw or any other suitable implant.

As shown in step 616, any number of finishing steps may be performedincluding steps performed immediately after placement and stepsperformed at a later time such as steps relating to, e.g., aestheticsand fit of a crown, abutment, or other dental object affixed to animplant.

As described above, the first cutting tool and the second cutting toolmay be the same or different, and may include any tool usefully employedby a surgeon including without limitation a drill, a surgical drill, arotary tool, and a surgical hand tool. The present invention is in noway limited by the type of surgical tools or instruments employed.Additionally, as noted above, the guides or guide layers employed mayinclude any of the surgical guides and/or supports described herein.More generally, the order in which the steps of the present method areperformed is purely illustrative in nature, and the individual steps maybe re-ordered, removed, supplemented, modified, or otherwise alteredwithout departing from the scope of this disclosure.

For example, in one aspect, a bleeding point may be manually positionedby a surgeon without the assistance of a guide, and the “second guide”described above may be used with the manually positioned bleeding pointto align a drill to the axial trajectory. Thus in one aspect there isdisclosed herein a method that includes creating a bleeding point at afirst point on a target surface and guiding a drill with a guide thatincludes a hole spaced away from the target surface. The guide mayinclude a thin layer guide with a computer-positioned hole that iscreated using any of the techniques described above.

By way of further example, a variety of combinations of automated andmanual steps, and/or combinations of computerized and physicalmanipulations may be used consistent with the scope of this disclosure.A physical impression may be used to create a shell for a thin layerguide, or the thin layer guide may be fabricated using stereolithographyor any other suitable computerized fabrication technique from a digitalmodel that includes the guide holes or a combination of these techniquesmay be employed. In another aspect, a physical dental model (e.g., froma physical impression) may be scanned to digitize surface data, and thisdata may be combined with CT scan data to plan a trajectory for aprocedure, after which a digital model of a guide including one or moreguide holes may be directly fabricated using any suitable computerizedfabrication technique. Or a shell for a physical thin layer guide may beobtained from a physical dental model and digitized with any suitablescanning technique such as a surface scanning technique or x-raytomography to provide a digital model of the shell, and holes may beplaced within the shell in a computer modeling environment. In thislatter example, the resulting digital drill guide model may be used toplace holes in the physical thin layer guide (with a computerized ormanual fabrication step), or the digital drill guide model may be usedfor direct fabrication of an entire, final drill guide. In anotheraspect, a three-dimensional surface scanning technique may be used toobtain an initial, digital impression of the surgical site (andsurrounding dentition), which may in turn be used to fabricate aphysical model using any suitable computerized fabrication technique.This physical model may be used in lieu of the physical impression inany of the foregoing procedures. Still more generally, the guidesdescribed herein may be fabricated using many combinations of steps withphysical and/or digital models, based upon many combinations of sourcedata (e.g., surface scans, CT scans, etc.), and using a variety ofcomputerized and/or manual fabrication techniques. All such combinationsthat can be used to obtain a physical realization of a guide asdescribed herein are intended to fall within the scope of thisdisclosure.

By way of further example, a variety of combinations of automated andmanual steps, and/or combinations of computerized and physicalmanipulations may be used consistent with the scope of this disclosure.A physical impression may be used to create a shell for a thin layerguide, or the thin layer guide may be fabricated using stereolithographyor any other suitable computerized fabrication technique from a digitalmodel that includes the guide holes, or a combination of thesetechniques may be employed. In another aspect, a physical dental model(e.g., from a physical impression) may be scanned to digitize surfacedata, and this data may be combined with CT scan data to plan atrajectory for a procedure, after which a digital model of a guideincluding one or more guide holes may be directly fabricated using anysuitable computerized fabrication technique. In another aspect, a shellmay be obtained from a physical dental model, and the shell may bedigitized using any suitable three-dimensional scanning technique suchas a three-dimensional surface scan or x-ray tomography to provide adigital model of the shell, and holes may be placed within the digitalmodel of the shell in a computer modeling environment to provide adigital drill guide model. A physical drill guide may then be fabricatedfrom the digital drill guide model using stereolithography or any othersuitable rapid prototyping or fabrication technique. The digital drillguide model may also or instead by used to control an automated drillingmachine to place holes in the shell, thus converting the shell into athin layer guide as described above.

In another aspect, a three-dimensional surface scanning technique may beused to obtain an initial, digital impression of the surgical site(and/or surrounding dentition), which may in turn be used to fabricate aphysical model using any suitable computerized fabrication technique.This physical model may be used in lieu of the physical impression inany of the foregoing procedures. Still more generally, the guidesdescribed herein may be fabricated using many combinations of steps withphysical and/or digital models, based upon many combinations of sourcedata (e.g., surface scans, CT scans, etc.), and using a variety ofcomputerized and/or manual fabrication techniques. All such combinationsthat can be used to obtain a physical realization of a guide asdescribed herein are intended to fall within the scope of thisdisclosure.

More generally, numerous methods may be employed for fabricatingsurgical guides as described herein. By way of further illustrativeexample, and not by way of limitation, a number of additional, specificmethods are now described. In one embodiment, three-dimensional data maybe obtained from a patient's dental arch with a physical dentalimpression, which may in turn be used to fabricate a physical model ofthe arch. An acrylic sheet or the like may then be formed onto thephysical model to obtain a shell. The shell may then be used tofabricate a radiographic stent that includes a radiopaque marker of thefuture tooth position and one or more fiduciary markers (e.g., threefiduciary markers). Three-dimensional x-ray tomography data may then beobtained directly from the patient while the patient is wearing theradiographic stent (e.g., the shell with the fiduciary markers).Three-dimensional x-ray tomography data may also be obtained from theradiographic stent alone (e.g., without the patient's dentition) toprovide source data for the drill guide. Implant planning software maythen be used to determine an implant trajectory to provide implant data,and the implant data may be combined with the three-dimensional datafrom the radiographic stent alone to provide a digital model. The drillguide may then be fabricated from this three-dimensional data set (thedigital model of the drill guide), with any suitable modifications,adaptations, or other processing for output to a stereolithographysystem or stereolithography design environment. In the stereolithographydesign environment, which may be conventional stereolithography softwareor software customized for designing and fabricating drill guides asdescribed herein, implant trajectories in the form of guide holes may beimposed on the digital model based open the implant trajectories. Theshell may also be further modified to remove or add to surfaces thereof,such as to provide windows, alignment marks, and so forth, or to removeportions of the shell that are not required for support of the guide orotherwise not desired. The resulting digital model, with anymodifications as described above, may then be fabricated usingstereolithography or any other suitable fabrication technique.

In another aspect, an initial digital model of a patient's dental archmay be obtained directly from the patient using any suitablethree-dimensional surface scanning technique such as video-basedscanning, structured light scanning, and so forth. A shell may becreated from the initial digital model within a computer designenvironment, and used to fabricate a shell corresponding to thepatient's dental arch with, e.g., stereolithography. The shell may thenbe used to create a radiographic stent and the method may proceed asdescribed above.

In another aspect, the drill guide may be more generally hand-tooled.For example, three-dimensional surface data may be obtained from apatient's dental arch with a physical dental impression, which may beused in turn to fabricate a physical dental model using knowntechniques. A shell may be vacuum formed to the physical dental model,and the shell may be used to fabricate a radiographic stent as describedabove. Three-dimensional data may then be captured of a patient wearingthe radiographic stent, and the resulting data set may be used withinimplant planning software to determine an appropriate implanttrajectory. The coordinates that define the implant trajectory may bephysically transferred to the shell using any suitable technique, andone or more holes may be manually drilled or otherwise created in theshell to provide a drill guide.

As previously noted, these specific examples are not intended to limitthe generality of the invention. Numerous other variations andadaptations to the foregoing are possible, and all such variations thatare apparent to one of ordinary skill in the art are intended to fallwithin the scope of this disclosure.

It will also readily be appreciated that a kit may be provided for asurgical procedure according to any of the foregoing. The kit may, forexample, include one or more of the guides described above, such as anumber of guides with progressively larger holes for an axialtrajectory. The kit may also include a corresponding collection ofdrills, such as disposable drills, or the holes may be sized for astandard dental or surgical drill set. The kit may also or insteadinclude a number of drill stops to achieve a predetermined drill depthfor a particular procedure, or drill stops for a surgeon to variablycontrol depth. In another aspect, the corresponding collection of drillsmay be fabricated to include a drill stop, such as by manufacturingdrill bits with varying diameter sections. The kit may also or insteadinclude a variety of related components, such as written instructionsfor a procedure, computerized instructions for a procedure (on a compactdisk or other storage medium), sterilization materials, dental models,implant screws, and so forth. The kit, or portions thereof, may bepackaged in a sterile packaging. More generally, any assembly andpackaging of components and materials to accompany the drill guidesdescribed herein may usefully be provided as a kit for dental or othersurgical use.

FIG. 7 shows a two-layer surgical guide. As depicted, a device 700,which may include some or all of the features of any of the devicesdescribed herein, may include two or more separate layers integratedinto a single guide. More specifically, the device 700 may include afirst hole 702 in a first layer 704 positioned to align a tool or thelike to an axial trajectory at a first point along the axial trajectoryand a second hole 706 in a second layer 708 spaced apart from the firstlayer, the second hole 708 positioned to align the tool to the axialtrajectory at a second point along the axial trajectory, all asgenerally discussed above. More specifically, the first layer 704 may bevertically spaced apart from the second layer 708 along the axialtrajectory so that the first hole 702 and the second hole 706 can fullydefine the axial trajectory as generally described herein. Any number ofadditional holes for additional axial trajectories may also be included.The device 700 may include a support 710, such as any of the supportsdescribed above, to secure the surgical guide in relation to a locationwhere the axial trajectory meets a target surface of a surgical site. Asdepicted, the first layer 704 may be attached to the support 710 on asingle end thereof to provide full physical and visual access to thesurgical site and surrounding areas. In another aspect, a second end ofthe first layer 704 may include a further support structure attached tothe second layer, such as along a rear edge of the layers, foradditional structure support and rigidity. In another aspect, the device700 may include side walls between the first layer 704 and the secondlayer 708 fully or partially enclosing a space between the two layers.More generally, a variety of supporting configurations and structuresmay be included in the device 700, and all such variations are intendedto fall within the scope of this disclosure.

The first hole 702 may have the same diameter as the second hole 706. Inother embodiments, the second hole 706 may have a smaller diameter thanthe first hole 702 (or alternatively stated, the first hole 702 may havea larger diameter than the second hole 706) so that, for example, adrill stop or the like may be used with a drill, where the drill stop issized to fit through the first hole 702 but not through the second hole706. The first layer 704 and the second layer 708 may be sufficientlyspaced apart to provide a space for an insertion of a tool into thefirst hole 702 off-axis from the axial trajectory.

In one aspect, the guide may be fabricated using two separate physicalmodels of the surgical site. For example a first model may be obtainedwith tooth or teeth that are to be replaced by an implant-supportedcrown. A layer formed on this first model may provide a layer away fromthe target surface to define a first point along the axial trajectory. Asecond model may be obtained with the tooth (or teeth) removed so that alayer formed on this model rests directly against the target surface ofthe surgical site. The first layer may then be molded onto or otherwiseattached to the second layer in various support areas to provide a onepiece, two layer guide. In another aspect, the entire device 700 may befabricated from a computerized model or the like as generally discussedabove.

FIG. 8 is a cross-sectional view of a two-layer surgical guide. Thedevice 800 may include any of the devices or features described herein.As shown, the device 800 may include a first guide 802 formed by a firsthole 804 in a first layer 806 and a second guide 808 formed by a secondhole 810 in a second layer 812 which may include any of the guides,holes, and layers described above. The first guide 802 and the secondguide 808 may be integrated into a single device to provide a fullspatial definition for an axial trajectory 816 for a tool 818. Thus forexample, the first guide 802 may align the tool 818 at a point away froma target surface 814 while the second guide 808 may align the tool 818where the axial trajectory 816 meets the target surface 814.

This arrangement may advantageously reduce the number of separatedevices required for a surgical procedure. For example, the device 800may permit an off-axis insertion of the tool 818 along a second axis 820as depicted, thus decreasing the intraoral clearance required to insertthe tool 818 into the device 800. The space between the first layer 806and the second layer 812 may also be accessible through a window or thelike to provide physical and/or visual access to the surgical siteand/or the axial trajectory 816. In general, the device 800 may beformed to rest upon a target surface 814 and provide tooth support, softtissue support, and/or bone support as generally discussed above. Itwill be noted that the device 800 is depicted with side walls forsupport of the first guide 802 that might run along a dental arch, whilethe device 700 of FIG. 7 provides end support for an upper guide. Ingeneral, side walls, end walls, or any other supporting structure(s), aswell as combinations of these, may also or instead be employed to securea guide in a desired location away from a target surface, and all suchvariations are intended to fall within the scope of this disclosure. Itwill further be appreciated that, while two side walls are depicted inthe cross-sectional view of FIG. 8, a cross section of the guide mayinclude a window or opening on either side or both sides, as shown forexample in the figures above. Thus while the first hole 804 and thesecond hole 810 are generally fixed relative to one another in atwo-layer guide, there is no requirement of any particular shape orarrangement of supporting structure(s) used to maintain this spatialrelationship unless otherwise explicitly stated to the contrary.

Numerous variations will be readily appreciated. In one aspect, thedevice 800 may include any number of additional layers, each providing aguide at a different distance from the target surface 814. In anotheraspect, one or more of the plurality of guides may be formed of acuttable material while one or more other ones of the plurality ofguides may be formed of a cut-resistant material, or include a sleeve orthe like to resist cutting. Where a cuttable material is used, theguide(s) may be modified before or during use by cutting or otherwisemodifying the hole(s) therein.

FIG. 9 is a cross-sectional view of a two-layer surgical guide. Thedevice 900 may be any of the surgical devices described above, such asthe device 800 of FIG. 8. As shown in FIG. 9, after a tool 902 isinserted into a first hole of the device 900 (either on-axis oroff-axis), a tip of the tool 902 may be directed toward the second hole,thus bringing the tool into alignment with a desired axial trajectory.

It will be appreciated from the foregoing that a window may be usefullyincorporated into a surgical guide for visual and/or physical access toa surgical site. Using a thin-layer construction as described, forexample, with reference to FIG. 5, a window may be formed directly inthe surgical guide (or the surrounding support) from an opening betweenthe layer and the target surface, or for a two-layer guide, between afirst layer and a second layer. For physical access, the window mayinclude a physical opening in the device. For visual access, a clear ortransparent region of material may also or instead be used. In anotheraspect, the entire device 900 may be fabricated of a clear plastic orother transparent material. The window may provide a view of the axialtrajectory where the axial trajectory intersects the layer, or anywhereelse between the layer and the target surface, and may generally providefor visual access or physical access to the surgical site.

FIG. 10 shows a surgical guide with a window. In general, a device 1000may include a surgical guide and a support as described above. Thedevice 1000 may also include a window 1002 bounded, for example, on foursides by the walls of the surgical guide. The window 1002 may provide aview of the axial trajectory where the axial trajectory intersects thetarget surface. The window 1002 may also or instead provide a view ofany other portions of the axial trajectory, or a drill or other toolinserted into the surgical guide and traveling along the axialtrajectory. The window 1002 may be formed with a transparent material inthe surgical guide, or the window 1002 may include a physical opening inthe surgical guide or the support that provides a view of the spacesurrounding the axial trajectory as well as physical access to thespace. More generally, the window may include any structures and/ormaterials that provide visual and/or physical access to an interiorspace 1004 of the device 1000. The interior space 1004 may becoextensive with a hole used to guide a drill, or the interior space1004 may include additional interior volume(s) of the device 1000, suchas regions that accommodate off-axis insertion of a tool as generallydiscussed above.

FIG. 11 depicts another embodiment of a window 1100 in a surgical guide1102. As shown in FIG. 11, the window 1100 may be formed from a slit orother opening bounded on two substantially vertical sides by the wallsof the surgical guide 1102 (or support). This window 1100 may proceedfrom a top to a bottom of the surgical guide 1102 or along any otherlength of the walls. In one aspect, the window 1100 may reach at leastto the target surface in order to provide visual inspection of a drillor other tool as it contacts the target surface.

FIG. 12 is a cross-sectional view of a surgical guide. It will be notedthat some of the surgical guides described above are designed to guide atool or the like at a first point along an axial trajectory whilepermitting excursions of the tool away from the axial trajectory atother points along the axial trajectory. This feature may be achievedusing a thin layer as discussed generally above. In another aspect, thisfeature may be achieved using a relatively thicker guide (e.g., of athickness used in prior art drill guides) with a funnel-shaped orsimilar geometry for a hole in the guide 1200. This geometry may confinea tool (not shown) at one point along the axial trajectory 1202, whilepermitting excursions such as off-axis insertion or use, at otherpoints. For example, as depicted in FIG. 12, a tool inserted into theguide 1200 may be confined at a point 1203 away from a target surface1204, but permitted to move away from the axial trajectory at otherlocations, such as positions closer to (or farther from) the targetsurface, or more generally to move away from the axial trajectory withina space 1206 within the guide 1200. Thus in one aspect a surgical guidedisclosed herein may include a hole that is tapered into a funnel shape.The guide may be thicker than the diameter of the funnel at its narrowend 1208 or, using a different benchmark, thicker than a diameter of atool matched to the guide 1200. It will be understood that while alinear funnel shape is depicted, any similar shape, such as an arc, aparabola, or any other regular or irregular wall profile that joins awider hole on one side of the surgical guide to a narrower hole on anopposing side (e.g., a drill entry side and a drill exit side or thelike) may be similarly employed without departing from the scope of thisdisclosure.

FIG. 13 is a cross-sectional view of a surgical guide. As with FIG. 12above, the surgical guide 1300 of FIG. 13 guides a tool at one pointalong an axial trajectory while permitting movement of the tool at otherpoints along the axial trajectory. More specifically with reference toFIG. 13, the surgical guide 1300 guides a tool of matched diameter wherean axial trajectory 1302 intersects a target surface 1304, whilepermitting excursions of the tool off the axial trajectory 1302 awayfrom the target surface 1304. Numerous similar arrangements will bereadily appreciated and are intended to fall within the scope of thisdisclosure, such as any cross-sectional profile that confines a tool toan axial trajectory at one or more points along the axial trajectorywhile permitting off-axis movement at other points along the axialtrajectory. In other embodiments, a narrowest portion of the hole may bebetween a top and bottom opening of the surgical guide. So for example,the hole may be wide at a top surface, taper to a narrower diameter inan interior portion of the guide, and then widen again to a relativelywider opening at a bottom surface. Still more generally, any profile forthe taper or interior shape of the hole consistent with the uses of adrill guide described herein may be suitably incorporated into thedevice without departing from the scope of this disclosure.

The funnel shape may also be usefully incorporated into a thin layerguide, such as to steer a tool into a hole or to narrow a layer at thehole to provide greater freedom of off-axis movement for amatched-diameter tool inserted therein. In addition, while the holesdescribed herein may useful employ a linear taper to provide a funnelshape as generally shown and described above, it will be understood thatother tapers may also or instead be employed, such as curvilinear tapersor compound tapers that variously increase and decrease as the hole istraversed from a top surface of the layer (e.g., away from the targetsurface) or a bottom surface (e.g., adjacent to the target surface).Thus the hole may more generally include a tapered wall with a diameterthat varies along an axis passing through the hole. The diameter may,for example, vary from a widest diameter on top to a narrowest diameteron the bottom (as in FIG. 13), or the diameter may range from anarrowest diameter on the top to a widest diameter on the bottom (as inFIG. 12). The narrowest diameter may instead be between the top andbottom surfaces of the layer to provide a dual-funnel shape. In anotheraspect, the narrowest section may extend from within the hole to abottom surface of the guide. This configuration may be employed in arelatively thick tube guide or the like to accommodate off-axisinsertion in a top, open funnel portion of the guide, while providinglonger side walls to axially constrain a drill in a lower, cylindricalportion of the guide. Thus more generally a variety of shapes for thehole may be provided that vary from a narrowest diameter section (toguide a drill) and wider diameter sections (to accommodate off-axismovement of the drill when the guide is in use), and all such variationsare intended to fall within the scope of this disclosure.

In this context, the “shape” refers to the cross-sectional, verticalprofile as depicted in FIGS. 12 & 13. Each hole also has a z-axis shape,e.g., a cross-sectional, horizontal profile, as depicted for example inFIG. 14. As discussed above, this latter shape may be any closed,two-dimensional shape, and it should be understood that the horizontalprofile may vary as the hole is traversed along an axis passing throughthe hole from surface to surface of the guide. Thus for example, thehole may have an elliptical or elongated shape on the top surface toaccommodate off-axis insertion of a drill, and may converge on acircular shape at a bottom surface of the guide (where the guidecontacts a target surface) to accurately position a drill on the targetsurface.

In one aspect, the layer may have a thickness less than the diameter atthe narrowest section. The layer may instead have a thickness greaterthan the diameter at the narrowest section. The layer may also orinstead have a thickness greater or less than the diameter at the widestsection. The diameter at the widest section may be at least ten percentgreater than the diameter at the narrowest section, twenty five percentgreater than the diameter at the narrowest section, fifty percentgreater than the varying diameter at the narrowest section, or any otherratio suitable for use as generally described herein. The widest sectionmay be on a top layer of the guide and the narrowest section may be onthe bottom layer of the guide. Alternatively stated, the narrowestsection may be at a surface of the guide proximal to a location where anaxial trajectory meets a target surface of a surgical site. Or thenarrowest section may be at a surface of the guide distal to thelocation where the axial trajectory meets the target surface of thesurgical site. In other embodiments, the narrowest section may bebetween a top surface and a bottom surface of a layer of the guide, suchas with the compound profiles discussed above.

The surgical guide 1300 may also include alignment marks (not shown),such as the alignment marks described below, to assist a user inaligning a tool to a desired trajectory.

FIG. 14 shows alignment marks for a hole in a surgical guide. A device1400 may include a surface 1402, which may be a top or visible surfacethat can be viewed by a user of the surgical guide during use. Thedevice 1400 may include a hole 1404 that serves as a surgical guide asgenerally described above. In addition, the device may include one ormore visible alignment marks 1406 to assist a user in locating a centerof the hole 1404 during use, or otherwise assist a user in centering atool such as a cutting tool on the axial trajectory. While depicted in acrosshair pattern, it will be appreciated that more or fewer marks maybe provided such as a grid or other regular pattern of lines or othershapes. The visible alignment marks 1406 may include raised or lowered(e.g., three-dimensional) surface features and/or colored or othervisual markings rendered in ink, or any other suitable markings, surfacetreatment or the like that are visible to a user. While a single layeris depicted, it will be further understood that the visible alignmentmarks 1406 may be provided on one or more layers of a multi-layersurgical guide, or any of the other guide devices described herein.

FIG. 15 shows a system for creating a surgical guide. The above methodsfor fabricating guides may in general be realized using a system 1500with a variety of components. For example, the system 1500 may include adata acquisition system 1502, a processing system 1504, and acomputerized fabrication system 1506.

The system 1500 may optionally include a data acquisition system 1502.The data acquisition system 1502 may, for example, include any of thedata acquisition systems described above. This may includethree-dimensional scanning systems for obtaining surface data fromdentition and surrounding dental structures, or this may includecomputerized tomography systems for capturing volumetric data and/orsubsurface structural data (e.g., from beneath the target surface of asurgical site) that may be usefully employed in the methods describedherein. The data acquisition system 1502 may also or instead, include aphysical interface such as a keyboard and mouse for manual entry ofinformation concerning a patient, a guide, a surgical plan, and soforth.

The system 1500 may optionally include a processing system 1504 such asa computer or other suitable processor or processing circuitry forperforming functions associated with the fabrication of a surgicalguide. This may include, for example a computer executing case planningsoftware or providing other tools to assist a clinician or labtechnician in receiving data, planning a surgical procedure, andspecifying a drill guide for the surgical procedure.

The system 1500 may optionally include a computerized fabrication system1506. This may be any computer-controlled fabrication system includingrapid prototyping systems using, e.g., stereo-lithography,three-dimensional printing, computerized milling, and so forth, or anyother computer-controlled machine or combination of machines describedherein. It will also be appreciated from the methods described above,that many steps in the methods described above may also, or instead,include manual procedures such as the creation of vacuum-formed moldsfrom dental models and so forth.

It will be appreciated that many of the above systems, devices, methods,processes, and the like may be realized in hardware, software, or anycombination of these suitable for the control, data acquisition, anddata processing described herein. This includes realization in one ormore microprocessors, microcontrollers, embedded microcontrollers,programmable digital signal processors or other programmable devices orprocessing circuitry, along with internal and/or external memory. Thismay also, or instead, include one or more application specificintegrated circuits, programmable gate arrays, programmable array logiccomponents, or any other device or devices that may be configured toprocess electronic signals. It will further be appreciated that arealization of the processes or devices described above may includecomputer-executable code created using a structured programming languagesuch as C, an object oriented programming language such as C++, or anyother high-level or low-level programming language (including assemblylanguages, hardware description languages, and database programminglanguages and technologies) that may be stored, compiled or interpretedto run on one of the above devices, as well as heterogeneouscombinations of processors, processor architectures, or combinations ofdifferent hardware and software. At the same time, processing may bedistributed across devices such as the various systems described above,or all of the functionality may be integrated into a dedicated,standalone device. All such permutations and combinations are intendedto fall within the scope of the present disclosure.

In other embodiments, disclosed herein are computer program productscomprising computer-executable code or computer-usable code that, whenexecuting on one or more computing devices (such as the devices/systemsdescribed above), performs any and/or all of the steps described above.The code may be stored in a computer memory, which may be a memory fromwhich the program executes (such as random access memory associated witha processor), or a storage device such as a disk drive, flash memory orany other optical, electromagnetic, magnetic, infrared or other deviceor combination of devices. In another aspect, any of the processesdescribed above may be embodied in any suitable transmission orpropagation medium carrying the computer-executable code described aboveand/or any inputs or outputs from same.

It will be appreciated that the methods and systems described above areset forth by way of example and not of limitation. Numerous variations,additions, omissions, and other modifications will be apparent to one ofordinary skill in the art. Thus, for example, while dental implantprocedures are clearly contemplated, this disclosure is not limited tooral surgery, but may facilitate any osteotomy, bone surgery, bonereplacement, or other surgical procedure requiring drilling into bone orhard tissue, or more generally any procedure involving alignment of atool to a desired trajectory. In addition, the order or presentation ofmethod steps in the description and drawings above is not intended torequire this order of performing the recited steps unless a particularorder is expressly required or otherwise clear from the context.

While particular embodiments of the present invention have been shownand described, it will be apparent to those skilled in the art thatvarious changes and modifications in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the following claims. The claims that follow are intended toinclude all such variations and modifications that might fall withintheir scope, and should be interpreted in the broadest sense allowableby law.

1. A device comprising: a surgical guide for a dental procedure, thesurgical guide including a first hole in a first layer, the first holepositioned to align a tool to an axial trajectory at a first point alongthe axial trajectory and the surgical guide including a second hole in asecond layer, the second layer vertically spaced apart from the firstlayer along the axial trajectory and the second hole positioned to alignthe tool to the axial trajectory at a second point along the axialtrajectory; and a support to secure the surgical guide in relation to alocation where the axial trajectory meets a target surface of a surgicalsite.
 2. The device of claim 1 wherein the target surface includes oneor more of soft tissue and bone.
 3. (canceled)
 4. The device of claim 1wherein the surgical site includes a dental implant site. 5-6.(canceled)
 7. The device of claim 1 wherein the first hole and thesecond hole are shaped and sized to align an object to the axialtrajectory including one or more of a drill, a surgical drill, a rotarytool, and a surgical hand tool.
 8. The device of claim 1 wherein thesupport includes a surface formed to dentition around the surgical site,thereby providing tooth support for the surgical guide.
 9. The device ofclaim 8 wherein the surface is formed to a full arch containing thesurgical site.
 10. The device of claim 1 wherein the support includes asurface formed to bone around the surgical site, thereby providing bonesupport for the surgical guide.
 11. The device of claim 10 wherein thesupport includes one or more bone attachment points for securing thedevice to a jawbone.
 12. The device of claim 1 wherein the supportincludes a surface formed to at least one of gingival and mucosa aroundthe surgical site, thereby providing soft tissue support for thesurgical guide. 13-14. (canceled)
 15. The device of claim 1 wherein thefirst layer contacts the target surface in an area surrounding the firsthole when the device is placed for use at the surgical site.
 16. Thedevice of claim 1 wherein the second layer is spaced apart from thetarget surface in an area surrounding the second hole when the device isplaced for use at the surgical site.
 17. The device of claim 16 whereinthe second hole has a diameter larger than the first hole.
 18. Thedevice of claim 1 further comprising a space between the first layer andthe second layer that permits an insertion of the tool off-axis from theaxial trajectory.
 19. The device of claim 1 wherein at least one of thefirst layer and the second layer includes one or more visible alignmentmarks to assist a user in locating a center of the first hole. 20-22.(canceled)
 23. The device of claim 1 further comprising a window for atleast one of visual inspection of the target surface and physical accessto the target surface while the surgical guide is in use.
 24. (canceled)25. The device of claim 1 wherein the device is fabricated from acuttable material.
 26. (canceled)
 27. The device of claim 1 furthercomprising a plurality of holes in each of the first layer and thesecond layer for a plurality of axial trajectories.
 28. The device ofclaim 1 further comprising a plurality of devices each including a thirdhole positioned to align one of a number of progressively largerdiameter drills to the first point on the axial trajectory. 29.(canceled)
 30. The device of claim 1 wherein at least one of the firsthole and the second hole has a sleeve that protects the surgical guideagainst a cutting edge of the tool.
 31. (canceled)
 32. The device ofclaim 1 wherein the surgical guide and the support are formed of a clearmaterial. 33-177. (canceled)
 178. The device of claim 1 wherein theaxial trajectory is determined using implant planning software.